Upright vacuum cleaners in all of their designs and permutations have become increasingly popular over the years. The upright vacuum cleaners generally incorporate a nozzle assembly and a canister assembly pivotally mounted to the nozzle assembly. Wheels on the nozzle and canister assemblies allow the vacuum cleaner to smoothly ride over the surface to be cleaned.
The canister assembly includes an operating handle that is manipulated by the user to move the vacuum cleaner back-and-forth across the floor. The canister assembly also includes either a bag-like filter or a separation chamber and filter combination that trap dirt and debris while substantially clean air is exhausted by a fan that is driven by an onboard electric motor. It is this fan and motor arrangement that generates the drop in air pressure necessary to provide the desired cleaning action.
In most upright vacuum cleaners sold today, a rotary agitator is also provided in the nozzle assembly. The rotary agitator includes tufts of bristles, brushes, beater bars or the like to beat dirt and debris from the nap of a carpet being cleaned while the pressure drop or vacuum is used to force air entrained with this dirt and debris into the nozzle of the vacuum cleaner.
As the vacuum cleaner is manipulated back-and-forth by the operator with the handle on the canister assembly, the nozzle assembly may be periodically lifted slightly from the floor. This lifting action adversely affects the cleaning efficiency of the vacuum cleaner. Further, during the cleaning of certain surfaces there is a tendency for vibration to develop in the vacuum cleaner as a result of the engagement of the rotary agitator against the particular surface being cleaned. This vibration is often transmitted through the control handle and is often annoying to the user. A need is therefore identified for an upright vacuum cleaner that addresses these problems in a manner to provide enhanced cleaning efficiency as well as vibration reduction.
U.S. Pat. No. 6,772,474 to Nishikori et al, entitled Upright Vacuum Cleaner With Spring Loaded Nozzle, discloses an upright vacuum cleaner incorporating a spring loaded nozzle wherein a downforce is placed on the entire nozzle assembly in order to provide more efficient and vibration free cleaning. The present invention relates to an upright vacuum cleaner or other floor care cleaning equipment (such as a power nozzle of a canister vacuum cleaner or an extractor) incorporating an agitator assembly that is pivotally mounted to the main housing or base section of a nozzle assembly that rides on wheels traveling over the surface to be cleaned.